Engine Horsepower?

Discussion in 'Performance Mods' started by joeranton, Mar 18, 2007.

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  1. joeranton

    joeranton Guest

    What would be the best way to get the most horsepower out of a chinese 80cc engine. Would it be a good idea to get the cylinder bored out slightly and get a bigger, lighter piston to fit the cylinder. Would that allow me to get more RPMs out of my engine. Please comment.

  2. srdavo

    srdavo Active Member


    these aluminum chinese engines have chrome plating on the cylinder walls.
    that allows for NO boring....or even honing for that matter. anybody..feel free to correct me...?
  3. thatsdax

    thatsdax Guest

    Boring and hopping up motor.

    Boring will ruin the motor. It has a coating, flame spray chrome and nickel type. Not a steel liner. The Flame spray is what allows the motors to be made inexpensively. Some Honda, Weed eaters and such use this technology. Not sure why anyone would want to hop up a Dax or Howell motor, being that they are plenty fast out of the box. Anything faster can not be safe for a bicycle and for sure the police will not like a bicycle going 50 or 60mph through town. Try your best to keep under the radar so that the police will not get mad at us motor assisted bicycle owners..Thanks...Enjoy the ride.
  4. azvinnie

    azvinnie Guest

    couldn't agree more. if you want more speed get a 32 or 36 tooth sproket. l changed from a 48 to a 36 and it's way faster and you'll defintely feel it, anyway good luck to boring it out :grin:
  5. Guest

    Guest Guest

    Boring = death to a Nikasil or similarly lined engine.
    Optimize what you have through proper carb adjustments and other things like aerodynamics and weight reduction.
    Buy a scooter or a motorcycle if you need more power.
  6. joeranton

    joeranton Guest

    Thanks for the informative information. I didn't know much about the cylinder walls. You guys really help out alot. Thanks for your time. This is becoming an addiction for me. I'm probably gonna come out with more crazy projects once I actually get my engine. THis will be my second. My first one was a 60cc. I wasn't too thrilled with the power.
  7. Lucius

    Lucius Guest

    thats not strictly true..... u can rebore a nikasil or similar plated bore you just have to get it replated after.. not that cheap...
  8. locoWelder

    locoWelder Guest

    or you can have them bored over and insert a handa 70 replacment sleve
  9. thatsdax

    thatsdax Guest

    I do not think there is.........

    I do not think there is enough meat to do any boring for any purpose.
  10. locoWelder

    locoWelder Guest

    Yes there is I have done it to two 80cc jugs so far, BUT!!! there's no room for mistakes you can blow right thought the side of the jug if done wrong
  11. vax

    vax Guest

    However, the cylinder can be re-nicasil-ed. At least www.emot.nl does this at europe.
  12. atcspaul

    atcspaul Guest

    i read on dax's sight about removing the baffle and drilling 2 holes in the long pipe inside. has anyone tried this and what size bit if it works. the bit in the picture does not look that small. http://thatsdax.com/BICYCLE_ENGINE_KIT_TIPS.html they say on the sight it will give you the biggest performance boost on the engine
    Last edited by a moderator: Oct 1, 2007
  13. gauge

    gauge Guest

    ats paul this is off topic but to ure question maybe alittle diffrence in low end power that it bascally a waste of time it it definity didnt get me and more revs outa the motor
  14. azbill

    azbill Active Member

    I cut the whole tube off (2" stub)
    seemed to give a boost and negligable increase in noise
  15. alesterfeind

    alesterfeind Guest

    Cut off Baffle

    I cut of the pipe down to 2 inches. I really didn't notice any more performance at all, but I really like the sound. It has a nice "putt-putt" to it.
  16. atcspaul

    atcspaul Guest

    thanks everyone. sounds like most were not thrilled by any power difference
  17. hot70cc

    hot70cc Guest

    I had my cylinder honed out after my bearings destroyed my piston, all is well so far. I guess its all in who wants to do it and if they are good at it. Have prolly 100 miles on my engine since honed out cylinder was done:grin:
  18. hot70cc

    hot70cc Guest

    oh by the way it runs much more smooth, not as jerky and boggy on the start up now.
  19. ultimusmaximus

    ultimusmaximus New Member

    hey joe, dude if you want to increase performance go for it bro... dont let anyone tell you its not possible... all it requires is a little thinking outside the box... start off by matching the intake and exhaust manifolds with the holes in the cylinder... then have your head/ cylinder skimmed down or just remove the base cylinder gasket and replace with rtv to increase commpression... if you want to spend some money and get technical get a pocket bike hp carb and expansion chamber, then you will notice some serious hp!!
  20. In going with the boring theme, wasn't there somebody on here that was going to have a friend bore out the cylinder and add a steel sleeve to it?.....I can't remember who it was but it is here somewhere.....I think he was going to do it mainly for increased reliability tho.

    PS - I'm thinking bang for the buck more performance could be had by milling the head for increased compression and doing a high performance porting job.